#define _CRT_SECURE_NO_WARNINGS 1

int missingNumber(int* nums, int numsSize) {
    int x = 0;
    for (int i = 0; i < numsSize; i++)
    {
        x += *(nums + i);
    }
    return (numsSize + 1) * (numsSize / 2.0) - x;

}
